Various navigation systems are known facilitating the task of finding the fastest and/or shortest route to a destination specified by the driver of a vehicle. The most commonly used form of navigation devices currently are GPS based navigation systems for cars, but a growing number of other mobile devices such as mobile phones, notebooks, smartcards and the like come with the function of dynamically assisting the owner in finding the right route to a preselected destination. Those systems are not limited to the use in cars; they can also assist bicyclers and pedestrians in finding their ways. In particular for long-distance travels in regions the driver is not familiar with, those systems tremendously facilitate the task of deciding which route to choose at each crossing. Navigation devices provide this function usually by a combination of geographical knowledge stored in the form of street-maps in combination with dynamically generated data on the current position of the vehicle, which is mapped to streets of the street-maps. Usually, the dynamic determination of the position is based on GPS data received from a satellite. The navigation system indicates its user, e.g. via a graphic display and/or a voice, which street to chose at every crossing or slip road.
Advanced versions of current navigation system provide the user with the additional convenience of receiving current traffic information, e.g. traffic jam information.
A considerable disadvantage of existing systems is that the entry of the destination is a tedious and time consuming task. Usually, the input means provided by mobile navigation devices for entering destination data, e.g. a postal address, are cumbersome to use. Due to the limited space available on most mobile processing devices, the user cannot make use of a large key board to enter long street and city names but rather has to turn or press a small set of buttons to specify an address. Not only is this approach time consuming, it is also dangerous in case the driver of a car enters the destination while driving. Therefore, most people do not use their navigation devices for routes they are familiar with, e.g. for their daily routes from home to work and back. However, turning off the navigation device for those well-known routes also has some drawbacks. A turned-off navigation device cannot inform the driver on current traffic-announcements. The driver may therefore loose time in traffic jams which could have been avoided if he had not turned off his navigation device.